Implement CCDictionary::writeToFile();
Use NSDictionay to do the job for iOS and Mac, and using tinyxml2 for other platform;
Use CCLOG instead of CCLog;
Add support for CCDictionary contains CCArray;
do it atomically;
Make sure XMLDocument is deleted; Code clean up; Add test;
Merge pull request #2361 from tiantian20007/dictStuff

Implement CCDictionary::writeToFile();